Pipe splitting apparatus with cable engagement system

ABSTRACT

Pipe splitting apparatuses and systems including a replaceable blade, and methods therefor, are provided. In various examples, a cable retention and release mechanism is configured to releasably engage a cable and includes one or more segments of a pipe splitting apparatus including a cable passage. A segmented collet includes tapered segments and is disposed within a tapered portion of a cable passage of the one or more segments. Channel surfaces of the tapered segments together form a cable channel through the segmented collet. The cable channel is configured to widen in a disengaged position of the segmented collet and narrow in an engaged position of the segmented collet. A spring is disposed within the spring pocket of the one or more segments to bias the segmented collet distally in the engaged position.

RELATED APPLICATIONS

This patent application claims the benefit of priority, under 35 U.S.C.§119(e), to U.S. Provisional Patent Application Ser. No. 61/248,753,filed on Oct. 5, 2009, which is incorporated herein by reference in itsentirety.

TECHNICAL FIELD

This patent document pertains generally to pipe splitting and moreparticularly, but not by way of limitation, to a pipe splittingapparatus with a cable engagement system.

BACKGROUND

Pipe, such as plastic, copper, lead pipe, and the like, has been usedfor connecting homes to and creating networks for utilities, forinstance, water, sewage, and natural gas. As pipes become older, theybreak down, crack, develop scaling on interior surfaces that can clogthe pipe, and the like and thereby require replacement.

A technique known as pipe bursting is currently used as a convenientmethod to replace underground pipe without the need to completelyexcavate the pipe needing replacement. A pipe breaking device, such asan expander or a mole, is pulled by a cable through the existing pipewhile it is still underground. The expander is designed to break, splitor burst the pipe, and at the same time push the old pipe into thesurrounding soil. The expansion of the old pipe allows the expander topull a replacement pipe into place.

In an example, pipe splitters are pulled through existing piping by anattached cable. Attachment and detachment of the cable to the pipesplitter typically requires disassembly of components that are threadedtogether and then subsequent reassembly. Often times, the threads of themating components are further held together with an adhesive material(Loctite®, for instance). As such, these components can be verydifficult to separate, and doing so is often made more difficult due todamaged threading from pipe splitting operations and/or from repeatedassembly and disassembly of the components. Such disassembly andreassembly can be time consuming and difficult, which increases the timeand expense of pipe splitting operations. Also, depending upon theamount of thread damage incurred, the components may requirereplacement, which further adds to the expense of drilling operations.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsdescribe substantially similar components throughout the several views.Like numerals having different letter suffixes represent differentinstances of substantially similar components. The drawings illustrategenerally, by way of example, but not by way of limitation, variousembodiments discussed in the present document.

FIG. 1 is a side elevational view of an example of a pipe splittingapparatus with an example of a cable engagement system;

FIG. 2 is a cross-sectional view of the pipe splitting apparatus of FIG.1, the cross section taken along line 2-2 in FIG. 1;

FIG. 3 is a front elevational view of the pipe splitting apparatus ofFIG. 1;

FIG. 4 is a side elevational view of an example of a pipe splittingapparatus with an example of a cable engagement system;

FIG. 5 is a cross-sectional view of the pipe splitting apparatus of FIG.4, the cross section taken along line 5-5 in FIG. 4;

FIG. 6 is an end view of the pipe splitting apparatus of FIG. 4;

FIG. 7 is side perspective view of an example of a pipe splittingapparatus with an example of a cable engagement system;

FIG. 8 is a side elevational view of the pipe splitting apparatus ofFIG. 7;

FIG. 9 is a front elevational view of the pipe splitting apparatus ofFIG. 7;

FIG. 10 is a top plan view of the pipe splitting apparatus of FIG. 7;

FIG. 11 is a cross-sectional view of the pipe splitting apparatus ofFIG. 7, the cross section taken along line 11-11 in FIG. 10;

FIG. 12 is a side perspective view of an example of an extraction toolfor removal of a cable from examples of pipe splitting apparatuses withexamples of cable engagement systems;

FIG. 13 is a top plan view of the extraction tool of FIG. 12;

FIG. 14 is a side elevational view of the extraction tool of FIG. 12;and

FIG. 15 is a front elevational view of the extraction tool of FIG. 12.

DESCRIPTION OF THE EMBODIMENTS

The present inventor has recognized, among other things, that it isdesirable to provide a pipe splitting apparatus including a cableengagement system that allows for relatively easy engagement anddisengagement of the cable from the pipe splitting apparatus. Thepresent examples of the cable engagement system allow for relativelyquick engagement/disengagement of the cable from the pipe splittingapparatus with little to no disassembly of the pipe splitting apparatus.As such, the present examples of the cable engagement system are thoughtto be advantageous in that they potentially decrease downtime andexpenses incurred during pipe splitting operations.

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, and in which is shown byway of illustration specific embodiments in which the invention may bepracticed. These embodiments are described in sufficient detail toenable those skilled in the art to practice the invention, and it is tobe understood that other embodiments may be utilized and that structuralchanges may be made without departing from the scope of the presentinvention. Therefore, the following detailed description is not to betaken in a limiting sense, and the scope of the present invention isdefined by the appended claims and their equivalents.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In the appended claims, the terms “including” and“in which” are used as the plain-English equivalents of the respectiveterms “comprising” and “wherein.” Also, in the following claims, theterms “including” and “comprising” are open-ended, that is, a system,device, article, or process that includes elements in addition to thoselisted after such a term in a claim are still deemed to fall within thescope of that claim. Moreover, in the following claims, the terms“first,” “second,” and “third,” etc. are used merely as labels, and arenot intended to impose numerical requirements on their objects.

In the following description, the term cable is defined to include metalcables, wire rope, or other lengths of flexible line of suitablestrength to pull devices as described below through a section of pipe.These embodiments are described in sufficient detail to enable thoseskilled in the art to practice the invention. Other embodiments may beutilized and structural, or logical changes, etc. may be made withoutdeparting from the scope of the present invention.

Referring to FIGS. 1-3 and 12-15, an example pipe splitting apparatus100 is shown. In an example, the pipe splitting apparatus 100 includes afront segment 110, a pilot segment 130, and a nose segment 140. Thefront segment 110 includes a cable passage 102 configured to accept acable or wire therein to enable pulling of the pipe splitting apparatus100 in a pulling operation to split a pipe, conduit, or other object.The pilot segment 130 includes one or more blades 132 extending from anouter surface of the pilot segment 130. The blades, in an example, cut,split, score, scrape, or otherwise act upon the pipe or conduit during apipe splitting operation. The nose segment 140 includes an expanderportion 142, which, in this example, substantially conically expandsfrom a first diameter similar to that of the pilot segment 130 to asecond larger diameter, for instance, similar to that of the pneumatichammer segment. The second diameter, in an example, is large enough toaccommodate a replacement pipe or conduit to be advanced. The expanderportion 142 functions to further split and/or displace outwardly theexisting pipe to allow the replacement pipe or conduit to be advancedthrough the space previously occupied by the pipe or conduit beingreplaced. The pipe splitting apparatus 100, in an example, can becoupled to a pneumatic hammer segment, for instance, with a threadedportion 144 of the nose segment 140. The pneumatic hammer segment can beused to assist in urging the pipe splitting apparatus 100 through anexisting underground pipe or conduit to be replaced. In an example, thepneumatic hammer segment can be used in addition to pulling the pipesplitting apparatus 100 with the wire or cable extending from the cablepassage 102 of the front segment 110. In various examples, one or moreof these segments 110, 130, 140 can be used in various combinationsand/or used with other types of segments.

In an example, with specific reference to FIG. 2, the pipe splittingapparatus 100 includes a cable retention and release mechanism 120. Thecable retention and release mechanism 120 is configured to releasablyengage a wire or cable. The cable retention and release mechanism 120,in this example, is disposed within the front segment 110 and the pilotsegment 130. The cable retention and release mechanism 120 includes asegment extractor 122 disposed within a substantially tubular portion102A of the cable passage 102. In an example, the segment extractor 122is substantially tubular and configured to slide within thesubstantially tubular portion 102A of the cable passage 102. In afurther example, the segment extractor 122 includes at least one o-ringaround an outer surface of the segment extractor 122 to createfrictional resistance between the segment extractor 122 and thesubstantially tubular portion of the cable passage 102A to limit, slow,or otherwise retard sliding motion of the segment extractor 122 withrespect to the substantially tubular portion 102A of the cable passage102.

In an example, the cable retention and release mechanism 120 includes asegmented collet 124 disposed within a tapered portion 102B of the cablepassage 102. The segmented collet 124, in an example, includes taperedsegments 124A. In a further example, the segmented collet 124 includesthree tapered segments 124A, which, together, form a substantiallyfrusto-conical segmented collet 124. In another example, the segmentedcollet 124 includes more or less than three tapered segments 124A,which, together, form a substantially frusto-conical segmented collet124. In various examples, each tapered segment 124A includes an outerbearing surface 124B configured to abut the tapered portion 102B of thecable passage 102. The outer bearing surface 124B of the collectivetapered segments 124A, in some examples, forms a substantially taperedouter surface 124B of the segmented collet 124 corresponding to thetapered portion 102B of the cable passage 102. The tapered segments124A, in further examples, each include an inner channel surface 124C.The collective channel surfaces 124C of the tapered segments 124Btogether form a cable channel 124D through the segmented collet 124. Inan example, the cable channel 124D is configured to widen with proximalmotion of the segmented collet 124 within the tapered portion 102B toallow the cable to pass through the cable channel 124D in a disengagedposition of the segmented collet 124. In a further example, the cablechannel 124D is configured to narrow with distal motion of the segmentedcollet 124 within the tapered portion 102B to grip the cable in anengaged position of the segmented collet 124. In this way, proximalmotion of the segmented collet 124 within the tapered portion 102B ofthe cable passage 102 allows the tapered segments 124A to expandoutwardly, thereby widening the cable channel 124D through the segmentedcollet 124 to allow more space for movement of the cable or wire withinthe cable channel 124D of the segmented collet 124. Conversely, distalmotion of the segmented collet 124 within the tapered portion 102B ofthe cable passage 102 causes the tapered segments 124A to contractinwardly, thereby narrowing the cable channel 124D through the segmentedcollet 124 to decrease space within the cable channel 124D of thesegmented collet 124 to cause the channel surfaces 124C of the segmentedcollet 124 to bear down or otherwise grip the cable or wire. In anexample, the channel surfaces 124C include a gripping pattern to enhancea grip between the channel surfaces 124C and the cable or wire. In anexample, the segmented collet 124 includes at least one o-ring aroundthe segmented collet 124 to retain the tapered segments 124A in positionto form the segmented collet 124.

In an example, the pilot segment 130 includes a spring pocket 126disposed proximally from the cable passage 102. In a further example, aspring 128 is disposed within the spring pocket 126 of the pilot segment130. The spring 128, in this example, is configured to bias thesegmented collet 124 distally in the engaged position and inhibit thesegmented collet 124 from inadvertently remaining in the disengagedposition.

In an example, the segment extractor 122 is configured to abut a distalend of the segmented collet 124. In an example, the segment extractor122, which is disposed proximate to a front of the front segment 110, isreadily accessible to an operator of the pipe splitting apparatus 100.In this way, the segment extractor 122 can be moved proximally by theoperator to, in turn, move the segmented collet 124 proximally. In anexample, proximal movement of the segment extractor 122 causes thesegment extractor 122 to abut the segmented collet 124 (if not alreadyabutting the segmented collet 124) and move the segmented collet 124proximally to the disengaged position.

Although the cable retention and release mechanism 120 is shown anddescribed with respect to the front and pilot segments 110, 130, inother examples, it is contemplated that the cable retention and releasemechanism 120 is disposed within one or more other segments 110, 130,140 of the pipe splitting apparatus 100 or within other segments of thepipe splitting apparatus 100 not described herein.

Referring now to FIGS. 12-15, the segmented collet 124 is configured tobe moved proximally to the disengaged position using an extraction tool10. The extraction tool 10 includes a handle 12 including a head 14 at adistal end of the handle 12. The head 14 includes an extractor tube 16extending outwardly from the head 14. In an example, the extractor tube16 extends from the head 14 in a substantially perpendicular directionwith respect to the handle 12. In an example, the extractor tube 16includes a gap 18, which is configured to accept the cable or wire usedfor pulling the pipe splitting apparatus 100 to enable the cable or wireto be disposed within the extractor tube 16 during use of the extractiontool 10, as will be described in more detail below.

With further reference to FIGS. 1-3 and 12-15, in operation, to engagethe cable or wire with the cable retention and release mechanism 120 ofthe pipe splitting apparatus 100, the cable or wire is forced proximallywith respect to the pipe splitting apparatus 100 through the cablepassage 102. The cable or wire passes through the segment extractor 122and into the cable channel 124D of the segmented collet 124. Theproximal motion of the cable or wire causes the segmented collet 124 tomove proximally into the disengaged position to allow the cable or wireto move at least partially through the cable channel 124D of thesegmented collet 124. Once sufficient surface area of the cable channel124D is achieved the cable or wire can be pulled distally and/orproximal motion of the cable or wire can be ceased to allow the spring128 to act against the segmented collet 124 to move the segmented collet124 distally into the engaged position. In this way, the channelsurfaces 124C of the tapered segments 124A of the segmented collet 124are allowed to grip the cable or wire, thereby engaging the cable orwire within the pipe splitting apparatus 100 to allow the pipe splittingapparatus to be used in pipe splitting operations.

When it is desired to disengage the cable or wire from the cableretention and release mechanism 120, the extraction tool 10 can beplaced at the front of the front segment 110 with the cable or wiredisposed within the extractor tube 16 and a free end of the extractortube 16 abutting the segment extractor 122 within the cable passage 102.With distal force applied to the cable or wire (by the operator or byanother operator), proximal force is applied to the head 14 and orhandle 12 of the tool (for instance, force applied using a hammer) toforce the segment extractor and, in turn, the segmented collet 124proximally, thereby moving the segmented collet 124 into the disengagedposition. In an example, several hits with a hammer may be required.Once the segmented collet 124 is moved sufficiently proximally withrespect to the tapered portion 102B of the cable passage 102, the gripof the segmented collet 124 is sufficiently lessened to allow the cableor wire to be pulled out of the cable channel 124D of the segmentedcollet 124 and out from engagement with the cable retention and releasemechanism 120 of the pipe splitting apparatus 100.

Although described above as including a segment extractor 122, in otherexamples, it is contemplated that the cable retention and releasemechanism 120 need not include the segment extractor 122. For instance,the segmented collet 124 can be disposed sufficiently distally withinthe cable passage 102 so that the extraction tool 10 can reach thesegmented collet 124 to allow the extraction tool 10 to be used directlyagainst the segmented collet 124 to force the segmented collet 124 intothe disengaged position. In another example, the extractor tube 16 canbe of a length sufficient to reach the segmented collet 124 if thesegmented collet 124 is recessed from a front of the cable passage 102.

Referring to FIGS. 4-6 and 12-15, an example pipe splitting apparatus200 is shown. In an example, the pipe splitting apparatus 200 includes apilot segment 230, a segment cartridge 250, and a nose segment 240. Thepilot segment 230 includes a cable passage 202 configured to accept acable or wire therein to enable pulling of the pipe splitting apparatus200 in a pulling operation to split a pipe, conduit, or other object.The pilot segment 230 includes one or more blades 232 extending from anouter surface of the pilot segment 230. The blades, in an example, cut,split, score, scrape, or otherwise act upon the pipe or conduit during apipe splitting operation. The nose segment 240 includes an expanderportion 242, which, in this example, substantially conically expandsfrom a first diameter similar to that of the segment cartridge 250 to asecond larger diameter, for instance, similar to that of the pneumatichammer segment. The second diameter, in an example, is large enough toaccommodate a replacement pipe or conduit to be advanced. The expanderportion 242 functions to further split and/or displace outwardly theexisting pipe to allow the replacement pipe or conduit to be advancedthrough the space previously occupied by the pipe or conduit beingreplaced. The pipe splitting apparatus 200, in an example, can becoupled to a pneumatic hammer segment, for instance, with a threadedportion 244 of the nose segment 240. The pneumatic hammer segment can beused to assist in urging the pipe splitting apparatus 200 through anexisting underground pipe or conduit to be replaced. In an example, thepneumatic hammer segment can be used in addition to pulling the pipesplitting apparatus 200 with the wire or cable extending from the cablepassage 202 of the pilot segment 230. In an example, the pilot segment230 and the segment cartridge 250 include complementary rounded abuttingsurfaces to allow an amount of angular movement of the pilot segment 230with respect to the segment cartridge 250. In various examples, one ormore of these segments 230, 250, 240 can be used in various combinationsand/or used with other types of segments.

In an example, with specific reference to FIG. 5, the pipe splittingapparatus 200 includes a cable retention and release mechanism 220. Thecable retention and release mechanism 220 is configured to releasablyengage a wire or cable. The cable retention and release mechanism 220,in this example, is disposed within the segment cartridge 250. The cableretention and release mechanism 220 includes a segment extractor 222disposed within a substantially tubular portion 202A of the cablepassage 202. In an example, the segment extractor 222 is substantiallytubular and configured to slide within the substantially tubular portion202A of the cable passage 202. In a further example, the segmentextractor 222 includes at least one o-ring around an outer surface ofthe segment extractor 222 to create frictional resistance between thesegment extractor 222 and the substantially tubular portion of the cablepassage 202A to limit, slow, or otherwise retard sliding motion of thesegment extractor 222 with respect to the substantially tubular portion202A of the cable passage 202.

In an example, the cable retention and release mechanism 220 includes asegmented collet 224 disposed within a tapered portion 202B of the cablepassage 202. The segmented collet 224, in an example, includes taperedsegments 224A. In a further example, the segmented collet 224 includesthree tapered segments 224A, which, together, form a substantiallyfrusto-conical segmented collet 224. In another example, the segmentedcollet 224 includes more or less than three tapered segments 224A,which, together, form a substantially frusto-conical segmented collet224. In various examples, each tapered segment 224A includes an outerbearing surface 224B configured to abut the tapered portion 202B of thecable passage 202. The outer bearing surface 224B of the collectivetapered segments 224A, in some examples, forms a substantially taperedouter surface 224B of the segmented collet 224 corresponding to thetapered portion 202B of the cable passage 202. The tapered segments224A, in further examples, each include an inner channel surface 224C.The collective channel surfaces 224C of the tapered segments 224Btogether form a cable channel 224D through the segmented collet 224. Inan example, the cable channel 224D is configured to widen with proximalmotion of the segmented collet 224 within the tapered portion 202B toallow the cable to pass through the cable channel 224D in a disengagedposition of the segmented collet 224. In a further example, the cablechannel 224D is configured to narrow with distal motion of the segmentedcollet 224 within the tapered portion 202B to grip the cable in anengaged position of the segmented collet 224. In this way, proximalmotion of the segmented collet 224 within the tapered portion 202B ofthe cable passage 202 allows the tapered segments 224A to expandoutwardly, thereby widening the cable channel 224D through the segmentedcollet 224 to allow more space for movement of the cable or wire withinthe cable channel 224D of the segmented collet 224. Conversely, distalmotion of the segmented collet 224 within the tapered portion 202B ofthe cable passage 202 causes the tapered segments 224A to contractinwardly, thereby narrowing the cable channel 224D through the segmentedcollet 224 to decrease space within the cable channel 224D of thesegmented collet 224 to cause the channel surfaces 224C of the segmentedcollet 224 to bear down or otherwise grip the cable or wire. In anexample, the channel surfaces 224C include a gripping pattern to enhancea grip between the channel surfaces 224C and the cable or wire. In anexample, the segmented collet 224 includes at least one o-ring aroundthe segmented collet 224 to retain the tapered segments 224A in positionto form the segmented collet 224.

In an example, the segment cartridge 250 includes a spring pocket 226disposed proximally from the cable passage 202. In a further example, aspring 228 is disposed within the spring pocket 226 of the segmentcartridge 250. The spring 228, in this example, is configured to biasthe segmented collet 224 distally in the engaged position and inhibitthe segmented collet 224 from inadvertently remaining in the disengagedposition.

In an example, the segment extractor 222 is configured to abut a distalend of the segmented collet 224. In an example, the segment extractor222, which is disposed proximate to a front of the segment cartridge250, is readily accessible to an operator of the pipe splittingapparatus 200 once the pilot segment 230 is slid proximally along thecable or wire and out of abutting relation with the segment cartridge250. In this way, the segment extractor 222 can be moved proximally bythe operator to, in turn, move the segmented collet 224 proximally. Inan example, proximal movement of the segment extractor 222 causes thesegment extractor 222 to abut the segmented collet 224 (if not alreadyabutting the segmented collet 224) and move the segmented collet 224proximally to the disengaged position.

Although the cable retention and release mechanism 220 is shown anddescribed with respect to the segment cartridge 250, in other examples,it is contemplated that the cable retention and release mechanism 220 isdisposed within one or more other segments 230, 250, 240 of the pipesplitting apparatus 200 or within other segments of the pipe splittingapparatus 200 not described herein.

Referring now to FIGS. 12-15, the segmented collet 224 is configured tobe moved proximally to the disengaged position using an extraction tool10. The extraction tool 10 includes a handle 12 including a head 14 at adistal end of the handle 12. The head 14 includes an extractor tube 16extending outwardly from the head 14. In an example, the extractor tube16 extends from the head 14 in a substantially perpendicular directionwith respect to the handle 12. In an example, the extractor tube 16includes a gap 18, which is configured to accept the cable or wire usedfor pulling the pipe splitting apparatus 200 to enable the cable or wireto be disposed within the extractor tube 16 during use of the extractiontool 10, as will be described in more detail below.

With further reference to FIGS. 4-6 and 12-15, in operation, to engagethe cable or wire with the cable retention and release mechanism 220 ofthe pipe splitting apparatus 200, the cable or wire is threaded throughthe pilot segment 230 and is forced proximally with respect to the pipesplitting apparatus 200 through the cable passage 202 of the segmentcartridge 250. The cable or wire passes through the segment extractor222 and into the cable channel 224D of the segmented collet 224. Theproximal motion of the cable or wire causes the segmented collet 224 tomove proximally into the disengaged position to allow the cable or wireto move at least partially through the cable channel 224D of thesegmented collet 224. Once sufficient surface area of the cable channel224D is achieved the cable or wire can be pulled distally and/orproximal motion of the cable or wire can be ceased to allow the spring228 to act against the segmented collet 224 to move the segmented collet224 distally into the engaged position. In this way, the channelsurfaces 224C of the tapered segments 224A of the segmented collet 224are allowed to grip the cable or wire, thereby engaging the cable orwire within the pipe splitting apparatus 200 to allow the pipe splittingapparatus to be used in pipe splitting operations.

When it is desired to disengage the cable or wire from the cableretention and release mechanism 220, the pilot segment 230 can be sliddistally along the cable or wire and out of abutting engagement with thesegment cartridge 250. The extraction tool 10 can be placed at the frontof the segment cartridge 250 with the cable or wire disposed within theextractor tube 16 and a free end of the extractor tube 16 abutting thesegment extractor 222 within the cable passage 202. With distal forceapplied to the cable or wire (by the operator or by another operator),proximal force is applied to the head 14 and or handle 12 of the tool(for instance, force applied using a hammer) to force the segmentextractor and, in turn, the segmented collet 224 proximally, therebymoving the segmented collet 224 into the disengaged position. In anexample, several hits with a hammer may be required. Once the segmentedcollet 224 is moved sufficiently proximally with respect to the taperedportion 202B of the cable passage 202, the grip of the segmented collet224 is sufficiently lessened to allow the cable or wire to be pulled outof the cable channel 224D of the segmented collet 224 and out fromengagement with the cable retention and release mechanism 220 of thepipe splitting apparatus 200.

Although described above as including a segment extractor 222, in otherexamples, it is contemplated that the cable retention and releasemechanism 220 need not include the segment extractor 222. For instance,the segmented collet 224 can be disposed sufficiently distally withinthe cable passage 202 so that the extraction tool 10 can reach thesegmented collet 224 to allow the extraction tool 10 to be used directlyagainst the segmented collet 224 to force the segmented collet 224 intothe disengaged position. In another example, the extractor tube 16 canbe of a length sufficient to reach the segmented collet 224 if thesegmented collet 224 is recessed from a front of the cable passage 202.

Referring to FIGS. 7-15, an example pipe splitting apparatus 300 isshown. In an example, the pipe splitting apparatus 300 includes a pilotsegment 330 and a nose segment 340. The pilot segment 330 includes acable passage 302 configured to accept a cable or wire therein to enablepulling of the pipe splitting apparatus 300 in a pulling operation tosplit a pipe, conduit, or other object. The pilot segment 330 includesone or more blades extending from an outer surface of the pilot segment330. The blades, in an example, cut, split, score, scrape, or otherwiseact upon the pipe or conduit during a pipe splitting operation. The nosesegment 340 includes an expander portion 342, which, in this example,substantially conically expands from a first diameter similar to that ofthe pilot segment 330 to a second larger diameter, for instance, similarto that of the pneumatic hammer segment. The second diameter, in anexample, is large enough to accommodate a replacement pipe or conduit tobe advanced. The expander portion 342 functions to further split and/ordisplace outwardly the existing pipe to allow the replacement pipe orconduit to be advanced through the space previously occupied by the pipeor conduit being replaced. The pipe splitting apparatus 300, in anexample, can be coupled to a pneumatic hammer segment, for instance,with a threaded portion 344 of the nose segment 340. The pneumatichammer segment can be used to assist in urging the pipe splittingapparatus 300 through an existing underground pipe or conduit to bereplaced. In an example, the pneumatic hammer segment can be used inaddition to pulling the pipe splitting apparatus 300 with the wire orcable extending from the cable passage 302 of the pilot segment 330. Inan example, the pilot segment 330 and the nose segment 340 includecomplementary rounded abutting surfaces to allow an amount of angularmovement of the pilot segment 330 with respect to the nose segment 340,as shown in FIGS. 7-11. In various examples, one or more of thesesegments 330, 340 can be used in various combinations and/or used withother types of segments.

In an example, with specific reference to FIG. 11, the pipe splittingapparatus 300 includes a cable retention and release mechanism 320. Thecable retention and release mechanism 320 is configured to releasablyengage a wire or cable. The cable retention and release mechanism 320,in this example, is disposed within the nose segment 340. The cableretention and release mechanism 320 includes a segment extractor 322disposed within a substantially tubular portion 302A of the cablepassage 302. In an example, the segment extractor 322 is substantiallytubular and configured to slide within the substantially tubular portion302A of the cable passage 302. In a further example, the segmentextractor 322 includes at least one o-ring around an outer surface ofthe segment extractor 322 to create frictional resistance between thesegment extractor 322 and the substantially tubular portion of the cablepassage 302A to limit, slow, or otherwise retard sliding motion of thesegment extractor 322 with respect to the substantially tubular portion302A of the cable passage 302.

In an example, the cable retention and release mechanism 320 includes asegmented collet 324 disposed within a tapered portion 302B of the cablepassage 302. The segmented collet 324, in an example, includes taperedsegments 324A. In a further example, the segmented collet 324 includesthree tapered segments 324A, which, together, form a substantiallyfrusto-conical segmented collet 324. In another example, the segmentedcollet 324 includes more or less than three tapered segments 324A,which, together, form a substantially frusto-conical segmented collet324. In various examples, each tapered segment 324A includes an outerbearing surface 324B configured to abut the tapered portion 302B of thecable passage 302. The outer bearing surface 324B of the collectivetapered segments 324A, in some examples, forms a substantially taperedouter surface 324B of the segmented collet 324 corresponding to thetapered portion 302B of the cable passage 302. The tapered segments324A, in further examples, each include an inner channel surface 324C.The collective channel surfaces 324C of the tapered segments 324Btogether form a cable channel 324D through the segmented collet 324. Inan example, the cable channel 324D is configured to widen with proximalmotion of the segmented collet 324 within the tapered portion 302B toallow the cable to pass through the cable channel 324D in a disengagedposition of the segmented collet 324. In a further example, the cablechannel 324D is configured to narrow with distal motion of the segmentedcollet 324 within the tapered portion 302B to grip the cable in anengaged position of the segmented collet 324. In this way, proximalmotion of the segmented collet 324 within the tapered portion 302B ofthe cable passage 302 allows the tapered segments 324A to expandoutwardly, thereby widening the cable channel 324D through the segmentedcollet 324 to allow more space for movement of the cable or wire withinthe cable channel 324D of the segmented collet 324. Conversely, distalmotion of the segmented collet 324 within the tapered portion 302B ofthe cable passage 302 causes the tapered segments 324A to contractinwardly, thereby narrowing the cable channel 324D through the segmentedcollet 324 to decrease space within the cable channel 324D of thesegmented collet 324 to cause the channel surfaces 324C of the segmentedcollet 324 to bear down or otherwise grip the cable or wire. In anexample, the channel surfaces 324C include a gripping pattern to enhancea grip between the channel surfaces 324C and the cable or wire. In anexample, the segmented collet 324 includes at least one o-ring aroundthe segmented collet 324 to retain the tapered segments 324A in positionto form the segmented collet 324.

In an example, the nose segment 340 includes a spring pocket 326disposed proximally from the cable passage 302. In a further example, aspring 328 is disposed within the spring pocket 326 of the nose segment340. The spring 328, in this example, is configured to bias thesegmented collet 324 distally in the engaged position and inhibit thesegmented collet 324 from inadvertently remaining in the disengagedposition.

In an example, the segment extractor 322 is configured to abut a distalend of the segmented collet 324. In an example, the segment extractor322, which is disposed proximate to a front of the nose segment 340, isreadily accessible to an operator of the pipe splitting apparatus 300once the pilot segment 330 is slid proximally along the cable or wireand out of abutting relation with the nose segment 340. In this way, thesegment extractor 322 can be moved proximally by the operator to, inturn, move the segmented collet 324 proximally. In an example, proximalmovement of the segment extractor 322 causes the segment extractor 322to abut the segmented collet 324 (if not already abutting the segmentedcollet 324) and move the segmented collet 324 proximally to thedisengaged position.

Although the cable retention and release mechanism 320 is shown anddescribed with respect to the nose segment 340, in other examples, it iscontemplated that the cable retention and release mechanism 320 isdisposed within the pilot segment 330 of the pipe splitting apparatus200, within both of the pilot and nose segments 330, 340, or withinother segments of the pipe splitting apparatus 300 not described herein.

Referring now to FIGS. 12-15, the segmented collet 324 is configured tobe moved proximally to the disengaged position using an extraction tool10. The extraction tool 10 includes a handle 12 including a head 14 at adistal end of the handle 12. The head 14 includes an extractor tube 16extending outwardly from the head 14. In an example, the extractor tube16 extends from the head 14 in a substantially perpendicular directionwith respect to the handle 12. In an example, the extractor tube 16includes a gap 18, which is configured to accept the cable or wire usedfor pulling the pipe splitting apparatus 300 to enable the cable or wireto be disposed within the extractor tube 16 during use of the extractiontool 10, as will be described in more detail below.

With further reference to FIGS. 7-15, in operation, to engage the cableor wire with the cable retention and release mechanism 320 of the pipesplitting apparatus 300, the cable or wire is threaded through the pilotsegment 330 and is forced proximally with respect to the pipe splittingapparatus 300 through the cable passage 302 of the nose segment 340. Thecable or wire passes through the segment extractor 322 and into thecable channel 324D of the segmented collet 324. The proximal motion ofthe cable or wire causes the segmented collet 324 to move proximallyinto the disengaged position to allow the cable or wire to move at leastpartially through the cable channel 324D of the segmented collet 324.Once sufficient surface area of the cable channel 324D is achieved thecable or wire can be pulled distally and/or proximal motion of the cableor wire can be ceased to allow the spring 328 to act against thesegmented collet 324 to move the segmented collet 324 distally into theengaged position. In this way, the channel surfaces 324C of the taperedsegments 324A of the segmented collet 324 are allowed to grip the cableor wire, thereby engaging the cable or wire within the pipe splittingapparatus 300 to allow the pipe splitting apparatus to be used in pipesplitting operations.

When it is desired to disengage the cable or wire from the cableretention and release mechanism 320, the pilot segment 330 can be sliddistally along the cable or wire and out of abutting engagement with thenose segment 340. The extraction tool 10 can be placed at the front ofthe nose segment 340 with the cable or wire disposed within theextractor tube 16 and a free end of the extractor tube 16 abutting thesegment extractor 322 within the cable passage 302. With distal forceapplied to the cable or wire (by the operator or by another operator),proximal force is applied to the head 14 and or handle 12 of the tool(for instance, force applied using a hammer) to force the segmentextractor and, in turn, the segmented collet 324 proximally, therebymoving the segmented collet 324 into the disengaged position. In anexample, several hits with a hammer may be required. Once the segmentedcollet 324 is moved sufficiently proximally with respect to the taperedportion 302B of the cable passage 302, the grip of the segmented collet324 is sufficiently lessened to allow the cable or wire to be pulled outof the cable channel 324D of the segmented collet 324 and out fromengagement with the cable retention and release mechanism 320 of thepipe splitting apparatus 300.

Although described above as including a segment extractor 322, in otherexamples, it is contemplated that the cable retention and releasemechanism 320 need not include the segment extractor 322. For instance,the segmented collet 324 can be disposed sufficiently distally withinthe cable passage 302 so that the extraction tool 10 can reach thesegmented collet 324 to allow the extraction tool 10 to be used directlyagainst the segmented collet 324 to force the segmented collet 324 intothe disengaged position. In another example, the extractor tube 16 canbe of a length sufficient to reach the segmented collet 324 if thesegmented collet 324 is recessed from a front of the cable passage 302.

In this way, the examples of cable retention and release mechanisms 120,220, 320 are believed to allow for relatively easy engagement anddisengagement of the cable from the pipe splitting apparatus 100, 200,300. The examples of the cable retention and release mechanisms 120,220, 320 allow for relatively quick engagement/disengagement of thecable from the pipe splitting apparatus 100, 200, 300 with little to nodisassembly of the pipe splitting apparatus 100, 200, 300. In this way,the examples of the cable retention and release mechanisms 120, 220, 320are thought to be advantageous in that they potentially decreasedowntime and expenses incurred during pipe splitting operations.

Other examples of collet engagement systems are shown and described inU.S. Provisional Application Ser. No. 61/144,064, filed on Jan. 12,2009, which application is incorporated herein by reference.

CONCLUSION

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments may be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. §1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription, with each claim standing on its own as a separateembodiment. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

What is claimed is:
 1. A cable retention and release mechanismconfigured to releasably engage a cable, the cable retention and releasemechanism comprising: one or more segments of a pipe splitting apparatusincluding a cable passage, the cable passage including a substantiallytubular portion and a tapered portion, the one or more segmentsincluding a spring pocket disposed proximally from the cable passage; asegmented collet disposed within the tapered portion of the cablepassage, the segmented collet including tapered segments, each taperedsegment including: an outer bearing surface configured to abut thetapered portion of the cable passage; and an inner channel surface,wherein the channel surfaces of the tapered segments together form acable channel through the segmented collet, the cable channel configuredto widen with proximal motion of the segmented collet within the taperedportion to allow the cable to pass through the cable channel in adisengaged position of the segmented collet, the cable channelconfigured to narrow with distal motion of the segmented collet withinthe tapered portion to grip the cable in an engaged position of thesegmented collet; a spring disposed within the spring pocket of the oneor more segments, the spring configured to bias the segmented colletdistally in the engaged position; and a segment extractor disposedwithin the substantially tubular portion of the cable passage.
 2. Thecable retention and release mechanism of claim 1, wherein the segmentedcollet includes three tapered segments.
 3. The cable retention andrelease mechanism of claim 1, wherein the segment extractor issubstantially tubular and configured to slide within the substantiallytubular portion of the cable passage, wherein proximal movement of thesegment extractor causes the segment extractor to abut the segmentedcollet and move the segmented collet proximally to the disengagedposition.
 4. The cable retention and release mechanism of claim 1,wherein the segment extractor includes an o-ring around an outer surfaceof the segment extractor, the o-ring configured to create frictionalresistance between the segment extractor and the substantially tubularportion of the cable passage.
 5. The cable retention and releasemechanism of claim 1, wherein the segmented collet includes an o-ringaround the segmented collet, the o-ring configured to retain the taperedsegments in position to form the segmented collet.
 6. The cableretention and release mechanism of claim 1, wherein the segmented colletis configured to be moved proximally to the disengaged position using anextraction tool.
 7. A pipe splitting apparatus comprising: a pipesplitting segment including a cable passage, the cable passage includinga substantially tubular portion and a tapered portion; a segmentedcollet disposed within the tapered portion of the cable passage, thesegmented collet including tapered segments, each tapered segmentincluding: an outer bearing surface configured to abut the taperedportion of the cable passage; and an inner channel surface, wherein theinner channel surfaces of the tapered segments together form a cablechannel through the segmented collet, the cable channel configured towiden with proximal motion of the segmented collet within the taperedportion to allow a cable to pass through the cable channel in adisengaged position of the segmented collet, the cable channelconfigured to narrow with distal motion of the segmented collet withinthe tapered portion to grip the cable in an engaged position of thesegmented collet, wherein the segmented collet is distally biased withinthe tapered portion of the cable passage; and a substantially tubularsegment extractor configured to slide within the substantially tubularportion of the cable passage, the segment extractor positioned distallyfrom the segmented collet, wherein proximal movement of the segmentextractor causes the segment extractor to abut the segmented collet andmove the segmented collet proximally to the disengaged position.
 8. Thepipe splitting apparatus of claim 7, comprising a spring disposed withinthe segment proximally from the segmented collet, wherein the spring isconfigured to distally bias the segmented collet.
 9. The pipe splittingapparatus of claim 8, wherein the segmented collet is biased in theengaged position.
 10. The pipe splitting apparatus of claim 8, whereinthe spring is disposed within a spring pocket of the segment, the springpocket disposed proximally from the cable passage.
 11. The pipesplitting apparatus of claim 7, wherein the segmented collet isconfigured to be moved proximally to the disengaged position using anextraction tool.
 12. The pipe splitting apparatus of claim 7, whereinthe inner channel surfaces of the tapered segments include a grippingpattern configured to enhance gripping of the cable with the innerchannel surfaces.
 13. A cable engagement system for a pipe splittingapparatus, the system comprising: a segmented collet disposed within atapered portion of a cable passage of the pipe splitting apparatus, thesegmented collet including tapered segments, each tapered segmentincluding: an outer bearing surface configured to abut the taperedportion of the cable passage; and an inner channel surface, wherein theinner channel surfaces of the tapered segments together form a cablechannel through the segmented collet, the cable channel configured towiden with proximal motion of the segmented collet within the taperedportion to allow a cable to pass through the cable channel in adisengaged position of the segmented collet, the cable channelconfigured to narrow with distal motion of the segmented collet withinthe tapered portion to grip the cable in an engaged position of thesegmented collet, wherein the segmented collet is distally biased withinthe tapered portion of the cable passage; and an extraction toolconfigured to be used to move the segmented collet proximally to thedisengaged position to allow insertion of the cable into or removal ofthe cable from the pipe splitting apparatus including: a handle and ahead; and an extractor tube extending outwardly from the head, whereinthe extractor tube is of sufficient length to reach and move thesegmented collet into the disengaged position when force is appliedproximally.
 14. The system of claim 13, wherein the extraction tool isconfigured to be at least partially inserted within the cable passage ofthe pipe splitting apparatus to move the segmented collet.
 15. Thesystem of claim 13, comprising a substantially tubular segment extractorconfigured to slide within a substantially tubular portion of the cablepassage, the segment extractor positioned distally from the segmentedcollet, wherein proximal movement of the segment extractor causes thesegment extractor to move the segmented collet proximally to thedisengaged position.
 16. The system of claim 15, wherein the extractiontool is configured to be used to move the segment extractor proximallyto move the segmented collet proximally to the disengaged position. 17.The system of claim 13, comprising a spring disposed within the pipesplitting apparatus proximally from the segmented collet, wherein thespring is configured to distally bias the segmented collet.
 18. Thesystem of claim 17, wherein the spring is disposed within a springpocket of the segment, the spring pocket disposed proximally from thecable passage.